Method of filtering solutions and recovering albumen.



NITED STATES" PArENr EEIoE.

ERIEDRIcII WILHELM HERMANN GRAEEE, or RUrI-IEREORD, NEw JERSEY, AND JosEPH E. GEIsLER, or NEw YORK, N. r.

METHOD OF FILTERING SOLUTIONS AND RECOVERING ALBUMEN.

n SPECIFICATION forming part of Letters Patent N0. 650,044, dated May 22, Application filed Tilly l2, 1898. Serial No. 685,742. (No` speoimens) To all whom it may concern/.-

Be it known that we, FRIEDRICH WILHELM HERMANN GRAEFE, residing at Rutherford,

New Jersey, and JOSEPH FRANK GEISLER, ref

siding at 1014c Trinity avenue, New York city, State of New York, have invented certain new and useful improvements in a method for the clarification of and rendering lilterable diilicultly-lterable solutions,especially solutions containing albumen or albumen -like substances, or for the removal or recovery of albumen from solutions; and we do hereby declare the following to be a full, clear, and ex actfdescription of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Our invention relates to improvements in processes for the coagulation of albumen and similar substances preparatory to their separation from fluids by filtration; and our invention consists in the novel steps of the process hereinafter described.

The objects of our invention are tocoagulate albumen and similar substances more efficiently than is possible by the processes heretofore in use and in such form that their separation from fluids by filtration may be conducted readily and rapidly. These objects are attained in the process herein described, an apparatus for the carrying out of which is illustrated diagrammatically in the drawing which accompanies and forms a part of this specification.

The difticulty of clarifying'fiuids containing albumen and similar substances and of separating such substances from the fluids containing them by methods heretofore known is well recognized. Such clarication and separation are usually conducted by coagulating the albumenoids and similar substances bythe action of heat or by the combined action of heat and pressure produced by the evaporation of the fluid in a closed vessel or by the action of chemical coagulative agents with or without the use of heat and pressure and then separating the substances'so coagulated from the fiuid by filtration; but it frequently happens that these methods of coagulatin g the albumenoids and similar substances fail to 4causecompletecoagulation thereof or cause them to coagulate coils of pipe within or surrounding the vesin finely-divided and slimy masses, which retard greatly the filtration or preventit entirely, thereby necessitating repeated reliandling and transferringof the solution to thev filter.

In our process the fluid to be treated I(after having added to it a suitable chemical coagulative agent, if chemical coagulative agents are to be use) is passed into a suitable closed 6b vessel, and an initial pressure of air or gas of from one to two atmospheres is applied to it therein. The Huid is then heated in a suitable manner, as by passing steam through sel, and as the temperature of the iiuid rises the pressure within the vessel may be raised, if necessary, sufficient pressure being always maintained, so that the boiling-point of the fluid is higher than its temperature. After the fluid has been raised to the desired temperature in this manner (this temperature usually ranging from 7 5 to 150 centigrade) and has been held at this temperature for a time we preferably lower the pressure in the vessel rapidly' by opening a suitable valve. 1f the iuid contains no vapors or gases which it is desired to retain therein or to save, We usually lower the pressure rapidly to atmospheric pressure; but if the Iiuid contains vapors or gases which it is desired to retain therein orto save the pressure is not allowed to fall so far as to cause such vapors or gases to come oit. The heating under pressure without boiling while the temperature of the iuid is being raised to the desired point and the subsequent release of the pressure causes the albumenoids and similar substances to coagulate in granular masses or clots, which may be separated readily from the iiuid'by filtration.

Our process is particularly applicable to the clarification of and removal of albumen and similar substances from beer,wines,vine gar, liquors, fruit-juices, such as sugar-cane juices, and other saccharine and gelatinous iuids and'solutions containing albumen and similar substances and to the removal of albumen from whey.

In the accompanying drawing there is illustrated,diagrammatically, an apparatus which may be employed for carrying out thc process.

IOO

, l is a suitable digester orvheatinrg vessel havingvv'vithlin it a heating-coil 2 and, preferd ably, stirrers 3, mounted upon a shaft 4.Y

5 is a pipe through Which the iiuid to be clarified may be admitted to theinterior "orL the digester.

`6f6 are a series of taps through which 4.the

fluid maybe drawnoifin'to a pipe 7, and Sis a pipe through which sediment remaining in the digester may be drawn oit. I

- 9 is a blow-oft pipe, 10 a pressure-gage, and l1 a pressure-pump by which air or gas pressure may be applied to the Huid Within the digester.

In carrying out our process we pass the iiuid into the digester l. If the heating is to tbe conducted in the presence of chemical cof agiilative agents, these agents may be added to the fluid before it is passedinto the digester'. VtTh'en the digester has been filled to the desired height, the valve in the'admission-pipe is closed and air or gas pressure of from one to t'Wo atmospheres is applied by means ofthe pump ll. Steam is then passed through the heating-coils 2 until the fluid Within the 'digester is heated to the desired y temperature, usually above 100"l eentigrade ergas; but vthe pressure maybe increased t the coils 2` i's-s'top'ped.

aidvhi'ch may reach 150C eentigrade. As the temperature of the fluid rises the pressure also rises, owing to the expansion of the air stillturther by the operation of the pump, if desred,being always maintained high enough t preventvaporization of thefl'uid. After die desired temperature@ the numA has been reached this temperature is maintained fora ti me,after which the passage of steamv through The content-sof the.

digester may then be'allovi'fed to cool, the al! and settling to the bottom of the digester.; but-We nd thatthis coagulation and settling maybe hastened by relieving the pressure in the digester'by opening the valve in' the pipe l It' the huid contains no, vapor lor gas which it is desired te retain in the huid or to save-the pressure maybe allowed to fall at once to atmospheric pressure. Otherwise the yb'unen andsim'ilar substances coagulatingY ally, beingV alwaysl kept highenugh to pre- Ivvue'ntthe escape-ot' the vapors or gases which itisdesired to retain. When the pressurehas been relieved and the coagulated matter has beeallotved to settle 'suiciently, the liquid, is drawn off through the'tap 6, and,..iin`ally, I. the coagulated matter, with a certain amount Y of liquid, is drawn off through the .pipeS. Thfeu'idthus drawn off is passed throughst litablefilters;` but because by the process abfve described the albumenoids or .similar substances coagulate in granular masses or clots the filtration may be conductedreadily.

As an 'illustration of our process We Will describe the method of clarifying; raw-sugar sol lutions.

We first make, a'jcncentrated,solution-.of

lution of albumen in Water in the proportion of from fifty -to one hundred grams of albumen Ato one hundred'quarts of sugar solution and stir the mixture thoroughly. The mixture is then placed in the digester, the pressure yin thev digester is raised to about thirty pounds per square inch by means of the compressie-n-pulnp,'and the contents of `the digester are heatedv to a temperature of about 125 centigrade. During the heating `the pressure in the digester rises because of the expansion of the air, and from time to time the air-pump is also operated, if necessary,*until when the desiredtemperature is reached thepressurey in the digester is about sixty pounds per square inch.` This pressure and the temperature of 125 centigrade are maintained for about fifteen kminutes, and then the blow-oit valve). is opened andthe pressure allow'ed to fall to atmospheric pressure, the evaporation cooling lthe contents of the digester down to about 100 centigrade; or, if preferred, the contents of the digester may be allowed to cool slowly Without opening the blow-off valve until the temperature within the digester isbelovv the boiling temperature .at atmospheric pressure and the Lpressure in the digester then relieved.f eithercase-when the ysolution has so cooled the albumen in it has coagulated in very nearly a granular form and has clarified the solution, so that all suspended or coagulable impurities are removed with the albumen when the 'latter is filtered out and the albumen has co= agulated'in such form thatiiltration is easy.

IOO

We have found by polarization tests that this treatment does not cause loss of sugar. d

Substantiallythe same treatment, Without the addition of albumen, may' be employed for the clarification of the sugar solution ob tained from su gar-cane, beets, and other vsug'arproducing vegetable growths in lieu of the customary heating of the solutionto remove albumen prior to shipping the syrup to the refineries. In thiscase thesolution is neutralized with lime-Water before 'the treatment is commenced. y

ThisV process may be conducted in such IIC)` manner as to effect theA separation of albu- .men and similar substances into grades.

Where this is to be done, the solution Whenfirst treated should have a decided acid reaction. After those albumens 'which will coagulat'e from the acid solutin have been coagulated bythe application of heat and pressure the fluid may be ilte'red or thec'oagulated albumen removed 'therefrom in any vother suitable manner, and then the acidity of the fluid may be reduced and heat and pressure applied anew in the. same 'manner as before. Whenthe fluid under treatment contains a number of dierent albumens, it, may be advisable to conduct the prcess by tW'o or more successive treatments, as above described, even if the iluid be not filtered be tween-.the treatments to separate the albu-s menoids into grades. If it be desired,A however, to coagulate the albumen in one operation, the solution should be nearly neutral before the application of heat and pressure,

as above described.

With the process above described may be combined-the charging or impregnating of the uid with a suitable gas, so as to convert the fluid into an aerated, carbonated, or other gas-charged liquid. Itis for this purpose particularly that the digester is provided with stirring-arms. In such case the gas by Which pressure is applied to the liquid Within the digester may be the gas with which the liquid is to be charged. Such gas may be caused to permeate through and combine with the liquid While the pressure is being applied, but before the heating is commenced, by operating the stirring-arms, so as to agitate the liquid.

When alburnen is heated in the presence of Water to a temperature equal to or exceeding about 140 centigrade under high pressure equal to or exceeding seven atmospheres, the albumen is absorbed by the water. The eect of the treatment in such cases is the exact reverse of the effect of the treatment above described for coagulating albu men. W'e have found that a moderate pressure of from two to four atmospheres applied from an external source and not produced by the evaporation of the fluid facilitates the coagulation of the albumen and causes it to coagulate in masses sufciently large to permit the ready filtration of the fluid.

Ordinarily in our process the temperature will not be raised above 140 centigrade, and

Vin no case does a harmful amount of resolution of the albumen occur.

Having thus completely described our invention, what We claim, and desire to secure by Letters Patent, is-

l. The herein-described process of clarifying luids containing albumen and similar substances, and coagulating such substances, which consists in heating such fluids and applying pressure thereto from an external source.

2. The hcrein-described process of clarifyvand raising the pressure progressively as the temperature of the fluid rises, so as to prevent evaporation of the fluid and to facilitate the coagulation.

4. The herein-described process of clarifyf ing fluids containing albumen and similar substances, which consists in applying heat and pressure to the fluid, the pressure being derived from an external source, and then rapidly decreasing the pressure.

5. The herein-described process of clarify# ing fluids containing albumen and similar substances, which consists in heating such fluids and applying thereto pressure derived from an external source, and maintained sufciently high to prevent evaporation of the fluid, and then suddenlydecreasing the pressure.

6. The herein-describedprocess of clarifying iluids containing albumen and similar substances, which consists in heating such fluids, in an acid condition, and applying thereto pressure derived from an external source, and maintained suflc-iently high to prevent evaporation of the fluid, and then decreasing the acidity and applying heat and pressure in the same manner.

In testimony whereof We alix our signatures in presence of Witnesses.

FRIEDRICH WILHELM HERMANN GRAEFF. JOSEPH Ii. GEISLER. W'itnesses:

F. G. HENRY, W. H. HEALY, Jos. A. KARL. 

